LAUSR

To the Editor: A 32-year-old man presented to the dermatology clinic with multiple asymptomatic blue lesions on the arms and upper torso of 15 years’ duration. His medical history was notable for a recent diagnosis of malignant melanoma following excision of a mole on the upper back 4 months prior. He reported that the mole had been present since childhood, but his sister noticed that it increased in size and changed in color over the course of a year. Physical examination showed multiple blue subcutaneous nodules on the bilateral arms and lower back. The nodules were soft and nontender, and some had telangiectasia on the overlying skin. Given the atypical distribution of nodules and the patient’s recent history of melanoma, there was concern for cutaneous metastases. A punch biopsy of one of the nodules on the right upper arm was performed. Microscopic examination of the biopsy specimen revealed a proliferation of multiple cavernous vessels surrounded by several rows of monotonous round cells with moderate eosinophilic cytoplasm and monomorphic nuclei, which was consistent with a diagnosis of glomangioma (Figure 1). Immunohistochemical analysis showed diffuse positive staining for smooth muscle actin (Figure 2); CD34 immunostain was positive in endothelial cells and negative in tumor cells (Figure 3). Two weeks after the first punch biopsy, the patient returned for follow-up. He noted a new soft, painless, nontender mass in the left axillary region. Positron emission tomography–computed tomography and a lymphoscintigram were performed to assess for lymphadenopathy, but they were not contributory. Subsequently, the patient underwent bilateral axillary sentinel lymph node dissection, which revealed the presence of metastatic melanoma in one lymph node in the left axilla. No metastatic disease was identified in the right axillary sentinel lymph nodes. A second skin biopsy was performed on another blue nodule to confirm the diagnosis and to exclude the possibility of sampling error. The histopathologic examination again revealed glomangioma, which established the diagnosis of multiple glomangiomas. Glomus tumors arise from modified smooth muscle cells located in glomus bodies. The glomus body is a component of the dermis involved in regulation of body temperature that is composed of an afferent arteriole and an efferent venule. The arterial end of this apparatus, known as the Sucquet-Hoyer canal, is surrounded by glomus cells that have a contractile capability similar to smooth muscle cells. Glomus tumors usually present as Multiple Glomangiomas in a Patient With a History of Metastatic Melanoma